The present disclosure relates to compositions such as weatherstrip compositions, weatherstrips that may be used in vehicles, and methods for forming the compositions and/or weatherstrips.
It is common in the motor vehicle industry to fashion decorative abrasion resistant sections for various parts of an automobile by extruding such sections from certain polymeric materials. Examples of typical abrasion resistant sections manufactured by such a process include weatherstrips. These weatherstrips are mounted on an automobile door surface and along the perimeter of automobile doors to provide a seal between the door and the automobile body as well as to protect both the door and exterior objects when they come in contact with each other. The weatherstrips may prevent wind noise, water leaks, and dust from entering the automobile.
Automotive glass run weatherstrip formulations typically utilize either thermoplastic vulcanizates (TPV) or ethylene propylene diene monomer (EPDM) rubber to achieve desired performance. TPVs are relatively easy to process but performance can be limited and material costs tend to be high. EPDM rubber formulations can require many ingredients (e.g., carbon black, petroleum-based oil, zinc oxide, miscellaneous fillers such as calcium carbonate or talc, processing aids, curatives, blowing agents, and many other materials to meet performance requirements). These ingredients are typically mixed together in a one or two step process prior to shipping to an extrusion facility. At the extrusion facility, the ingredients and rubber compound(s) are extruded into automotive glass run weatherstrips.
The extrusion process can include many stages depending on the type of EPDM weatherstrip being manufactured. For example, extrusion lines of up to 80 yards in length that are powered by natural gas and/or electricity may be required. Much of the natural gas and/or electricity is used to fuel hot air ovens, microwaves, infrared ovens, or other types of equipment used to vulcanize the EPDM rubber compounds. The vulcanization process also produces fumes that must be vented and monitored to comply with environmental requirements. This process can be very time consuming, costly, and environmentally unfriendly.
It would be desirable to develop new compositions and methods for manufacturing weatherstrips and windshield wipers which are simpler, lighter in weight, have superior long-term load loss (LLS) (i.e., ability to seal the glass and window for a long term), and more environmentally friendly.